Combustion device and water heating device

ABSTRACT

A combustion device including a chamber, a burner, a fan case, and a fan is provided. The chamber has a top wall. On the top wall, an inflow port penetrating through the top wall along a first direction and in communication with an internal space of the chamber is formed. The burner is attached to the chamber, so as to be spaced apart from and face the top wall in the first direction. In the fan case, a discharge port and an intake port penetrating through the fan case along the first direction and in communication with an internal space of the fan case are formed. The discharge port is connected with the inflow port. The fan is provided in the internal space of the fan case. A rotation axis of the fan is along the first direction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefit of Japan application serialno. 2020-212312, filed on Dec. 22, 2020. The entirety of theabove-mentioned patent application is hereby incorporated by referenceherein and made a part of this specification.

BACKGROUND Technical Field

The invention relates to a combustion device and a water heating device.

Description of Related Art

Patent Document 1 (Japanese Patent No. 6571445) discloses a combustiondevice. The combustion device disclosed in Citation 1 has a combustionchamber, an intake fan housing part, an intake fan, and a fan motor. Theintake fan is provided inside the intake fan housing part. An inflowport is formed on the top wall of the combustion chamber. With the fanmotor rotating the intake fan about the rotation axis along thehorizontal direction, a mixed gas is sucked into the inside of theintake fan housing part, and is supplied into the inside of thecombustion chamber through a mixed gas passage formed in the intake fanhousing part and the inflow port formed on the top wall.

Patent Document 2 (Japanese Patent No. 6534337) discloses a combustiondevice. The combustion device disclosed in Citation 2 has a burner bodymain body, a flat burner, a fan case, a fan, and a motor. The flatburner is provided to face the burner body main body in the top-downdirection, so as to block the internal space of the burner body mainbody. In the burner body main body, an inflow port open along thehorizontal direction is formed.

The fan is provided inside the fan case. In the fan case, the intakeport open along the horizontal direction is formed. The fan case isconnected, at a discharge port, to the inflow port of the burner bodymain body. Through the rotation of the fan, a mixed gas sucked into theinside of the fan case is supplied to an internal space of the burnerbody main body via the discharge port and the inflow port.

In the combustion device disclosed in Patent Document 1, since therotation axis of the intake fan is along the horizontal direction, thesize of the intake fan housing part in the top-down direction is large.In the combustion device disclosed in Patent Document 2, since theinflow port is open along the horizontal direction, the size of theburner body main body along the top-down direction is large. That is, itis difficult to reduce the height of the combustion device disclosed inPatent Document 1 and the combustion device disclosed in Patent Document2.

PRIOR ART LITERATURE Patent Documents

[Patent Document 1] Japanese Patent No. 6571445

[Patent Document 2] Japanese Patent No. 6534337

SUMMARY

A combustion device according to the invention includes a chamber, aburner, a fan case, and a fan. The chamber has a top wall. On the topwall, an inflow port penetrating through the top wall along a firstdirection and in communication with an internal space of the chamber isformed. The burner is attached to the chamber, so as to be spaced apartfrom and face the top wall in the first direction. In the fan case, adischarge port penetrating through the fan case along the firstdirection and in communication with an internal space of the fan case isformed. The discharge port is connected with the inflow port. The fan isprovided in the internal space of the fan case. A rotation axis of thefan is along the first direction.

In the combustion device, the fan case may have a bottom wall partiallyoverlapped with the chamber when viewed in a plan view. The dischargeport may be formed in a portion of the bottom wall overlapped with thechamber. In the combustion device, in a portion of the bottom wall notoverlapped with the chamber, a suction port penetrating through thebottom wall along the first direction and in communication with theinternal space of the fan case may be formed.

In the combustion device, the chamber may be further provided with afirst periphery wall surrounding the inflow port and having acylindrical shape protruding along the first direction. The fan case maybe further provided with a second periphery wall surrounding thedischarge port and having a cylindrical shape protruding along the firstdirection. The discharge port may be connected to the inflow port byinserting the second periphery wall into inside of the first peripherywall. A seal member may be provided between an inner periphery surfaceof the first periphery wall and an outer periphery surface of the secondperiphery wall.

In the combustion device, the inflow port may be located at a center ofthe chamber when viewed in a plan view. In the combustion device, thechamber and the fan case may be integrally formed.

A water heating device according to the invention includes a housing, afix member, and the combustion device. The housing is open on a side ofa second direction orthogonal to the first direction. The fan case isattached to the chamber by the fix member from a side of the chamber inthe second direction.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a water heating device 100.

FIG. 2 is a front view of a combustion device 200.

FIG. 3 is a plan view of the combustion device 200.

FIG. 4 is a cross-sectional view along IV-IV of FIG. 3.

FIG. 5 is a schematic perspective view of a housing 300.

DESCRIPTION OF THE EMBODIMENTS

Details of the embodiments of the invention will be described withreference to the drawings. In the following drawings, like or equivalentparts are labeled with the same reference symbols, and the samedescriptions will not be repeated.

The invention provides a combustion device and a water heating devicewhose height can be reduced.

Configuration of Water Heating Device According to an Embodiment

In the following, the configuration of a water heating device (waterheating device 100) according to an embodiment is described.

<Schematic Configuration of Water Heating Device 100>

FIG. 1 is a schematic view of the water heating device 100. As shown inFIG. 1, the water heating device 100 has a gas valve 10, an orifice 11,a venturi 12, a blowing device 13, a chamber 14, a burner 15, anignition plug 16, a primary heat exchanger 20, a secondary heatexchanger 30, a duct 40, a pipe 50, a pipe 60, a pipe 70, and a bypasspipe 80. The blowing device 13, the chamber 14, and the burner 15together are referred to as a combustion device 200. Details of thecombustion device 200 will be described in the following.

By making the gas valve 10 open, a fuel gas is supplied to the venturi12 via the orifice 11. The fuel gas supplied to the venturi 12 is mixedwith air in the venturi 12 (the fuel gas mixed with air is referred toas mixed gas in the following). The mixed gas is supplied to the burner15 via the chamber 14 by the blowing device 13. The mixed gas suppliedto the burner 15 is ignited and combusted by sparking the ignition plug16. Accordingly, a combustion gas is generated in the burner 15.

One end of the pipe 50 is connected to a water supply. The other end ofthe pipe 50 is connected to a water inlet port 30 a of the secondaryheat exchanger 30. One end of the pipe 60 is connected to a water outletport 30 b of the secondary heat exchanger 30. The other end of the pipe60 is connected to a water inlet port 20 a of the primary heat exchanger20. One end of the pipe 70 is connected to a water outlet port 20 b ofthe primary heat exchanger 20. The other end of the pipe 70 is connectedto a hot water tap (not shown).

One end of the bypass pipe 80 is connected to the pipe 50 and the otherend of the bypass pipe 80 is connected to the pipe 70. The bypass pipe80 and the pipe 70 are connected by using a three-way valve 71. The duct40 is connected to the secondary heat exchanger 30.

The water supplied from one end of the pipe 50 flows through the pipe 50to be supplied to the secondary heat exchanger 30. By performing heatexchange with the combustion gas, the temperature of the water suppliedto the secondary heat exchanger 30 is raised. The water flowing throughthe secondary heat exchanger 30 flows through the pipe 60 to be suppliedto the primary heat exchanger 20. By performing heat exchange with thecombustion gas, the temperature of the water supplied to the primaryheat exchanger 20 is raised.

The water flowing through the primary heat exchanger 20 is mixed withwater flowing through the bypass pipe 80 in the pipe 70. Accordingly,the temperature of the water is modulated. The water flowing through thepipe is supplied from the hot water tap. The combustion gas performingheat exchange with the water flowing through the primary heat exchanger20 and the secondary heat exchanger 30 is discharged to the outside fromthe duct 40.

The water heating device 100 is further provided with a housing 300. Thegas valve 10, the orifice 11, the venturi 12, the blowing device 13, thechamber 14, the burner 15, the ignition plug 16, the primary heatexchanger 20, the secondary heat exchanger 30, the duct 40, the pipe 50,the pipe 60, the pipe 70, and the bypass pipe 80 are accommodated insidethe housing 300.

<Detailed Configuration of Combustion Device 200>

FIG. 2 is a front view of the combustion device 200. FIG. 3 is a frontview of the combustion device 200. FIG. 4 is a cross-sectional viewalong IV-IV of FIG. 3. As shown in FIGS. 2 to 4, the combustion device200 has the blowing device 13, the chamber 14, and the burner 15.

The blowing device 13 has a fan case 131, a motor 132, and a fan 133.The fan case 131 has a top wall 131 a, a bottom wall 131 b, and a sidewall 131 c. The top wall 131 a and the bottom wall 131 b are spacedapart and face each other in a first direction DR1. The first directionDR1, for example, corresponds to the top-down direction. The side wall131 c is connected to the top wall 131 a and the bottom wall 131 b. Aninternal space of the fan case 131 is defined by the top wall 131 a, thebottom wall 131 b, and the side wall 131 c.

The fan case 131, for example, is provided to be partially overlappedwith the chamber 14 when viewed in a plan view (e.g., when viewed alongthe first direction DR). The portion of the fan case 131 overlapped withthe chamber 14 when viewed in a plan view is set as a first portion 131d, and the portion of the fan case 131 not overlapped with the chamber14 when viewed in the plan view is set as a second portion 131 e.

An intake port 131 f and a discharge port 131 g are formed in the fancase 131. The intake port 131 f and the discharge port 131 g are incommunication with the internal space of the fan case 131. The intakeport 131 f and the discharge port 131 g penetrate through the fan case131 along the first direction DR1. Specifically, the intake port 131 fis formed on the bottom wall 131 b in the second portion 131 e. Inaddition, the discharge port 131 g is formed on the bottom wall 131 b inthe first portion 131 d. Also, while not shown in the drawings, theventuri 12 is connected to the intake port 131 f.

A through hole 131 h is further formed in the fan case 131. The throughhole 131 h penetrates through the fan case 131 along the first directionD1, and is in communication with the internal space of the fan case 131.More specifically, the through hole 131 h is formed on the top wall 131a in the second portion 131 e.

The fan case 131 is further provided with a periphery wall 131 i. Theperiphery wall 131 i surrounds the periphery of the discharge port 131g. The periphery wall 131 i is in a cylindrical shape protruding fromthe outer surface of the bottom wall 131 b along the first directionDR1.

The motor 132 has a motor body 132 a and a shaft 132 b. The motor body132 a is provided on the top wall 131 a. The shaft 132 b extends alongthe first direction DR1. The shaft 132 b is inserted into the throughhole 131 h. The motor body 132 a rotates the shaft 132 b about thecentral axis of the shaft 132 b.

The fan 133 is provided in the internal space of the fan case 131. Thefan 133 is attached to the shaft 132 b. Therefore, with the motor body132 a rotating the shaft 132 b, the fan 133 rotates about the rotationaxis along the first direction in the internal space of the fan case131. Together with the rotation of the fan 133, the mixed gas is suckedinto the inside of the fan case 131 from the intake port 131 f. Inaddition, together with the rotation of the fan 133, the mixed gassucked into the inside of the fan case 131 is discharged from thedischarge port 131 g.

The chamber 14 has a top wall 141 and a side wall 142. An internal spaceof the chamber 14 is defined by the top wall 141 and the side wall 142.

An inflow port 141 a is formed on the top wall 141. The inflow port 141a penetrates through the top wall 141 along the first direction DR1. Theinflow port 141 a is in communication with the internal space of thechamber 14. The inflow port 141 a is formed at a portion of the top wall141 overlapped with the fan case 131, when viewed in a plan view. Theinflow port 141 a is connected to the discharge port 131 g. That is, themixed gas is supplied into the internal space of the chamber 14 via thedischarge port 131 g and the intake port 141 a. An inner diameter of theinflow port 141 a is referred to as an internal diameter D.

The chamber 14 is further provided with a periphery wall 143. Theperiphery wall 143 surrounds the periphery of the inflow port 141 a. Theperiphery wall 143 is in a cylindrical shape protruding from an outersurface 141 b of the top wall 141 along the first direction DR1. Aninner diameter of the periphery wall 143 is equal to or greater than anouter diameter of the periphery wall 131 i. By inserting the peripherywall 131 i into the inside of the periphery wall 143, the discharge port131 g and the inflow port 141 a are connected.

A seal member 144 is provided between the outer periphery surface of theperiphery wall 131 i and the inner periphery surface of the peripherywall 143. More specifically, a groove 131 j recessed toward the side ofthe inner periphery surface of the periphery wall 131 i is formed on theouter periphery surface of the periphery wall 131 i. The groove 131 j isformed in a ring shape. The seal member 144 is provided in the groove131 j. Accordingly, the space between the discharge port 131 g and theinflow port 141 a (between the periphery wall 131 i and the peripherywall 143) is hermetically sealed. The seal member 144, for example, isan O-ring.

The height of the chamber 14 is set as a height H. The height H is adistance between the outer surface 141 b and the lower end of the sidewall 142 (the end of the side wall 142 opposite to the top wall 141) inthe first direction DR1. The height H for example, is smaller than theinner diameter D.

In the following, a direction orthogonal to the first direction DR1 isset as a second direction DR2. The fan case 131 is attached to thechamber 14 by a fix member 145. More specifically, the fan case 131 isattached to the top wall 141 from one side of the second direction DR2by the fix member 145.

The burner 15 is attached to the chamber 14. The burner 15 is providedto be spaced apart from and face the top wall 141 in the first directionDR1. The burner 15 is attached to the side wall 142. By attaching theburner 15 to the chamber 14, the internal space of the chamber 14 isblocked.

In the burner 15, a flame hole (not shown in the drawings) is formed.The flame hole penetrates through the burner 15 along a thicknessdirection, and is in communication with the internal space of thechamber 14. The mixed gas supplied to the internal space of the chamber14 is ejected from the flame hole. Through the ignition by the ignitionplug 16, the mixed gas ejected from the flame hole is combusted, andflame is generated on the side of the outer surface of the burner 15.That is, the outer surface of the burner 15 becomes the combustionsurface of the burner 15.

FIG. 5 is a schematic perspective view of the housing 300. As shown inFIG. 5, the housing 300 has a top wall 301, a bottom wall 302, a sidewall 303, and a side wall 304. The top wall 301 and the bottom wall 302are spaced apart and face each other in the first direction DR1. Theside wall 303 and the side wall 304 are spaced apart and face each otherin a third direction DR3. The third direction DR3 is a directionorthogonal to the first direction DR1 and the second direction DR2. Thethird direction DR3 corresponds to the horizontal direction.

The housing 300 is further provided with a back wall 305. One end of thehousing 300 in the second direction DR2 becomes an opening part 306defined by the top wall 301, the bottom wall 302, the side wall 303, andthe side wall 304. The other end of the housing 300 in the seconddirection is blocked by the back wall 305. As described above, the fancase 131 is attached to the end part of the top wall 141 on one side ofthe second direction DR2 by the fix member 145. Therefore, the fixmember 145 is at a position visible from the opening part 306 of thehousing 300.

Effects of Combustion Device and Water Heating Device According toEmbodiment

In the following, the effects of the combustion device 200 and the waterheating device 100 are described.

In the combustion device 200, the direction of the rotation axis of thefan 133 is along the first direction DR1. Therefore, the size of the fancase 131 in the first direction DR1 can be reduced.

In the case where the inflow port 141 a is formed along a directionorthogonal to the first direction DR1, the size (height H) of thechamber 14 in the first direction DR1 cannot be reduced to be smallerthan the inner diameter D. However, in the combustion device 200, theinflow port 141 a is formed on the top wall 141 along the firstdirection DR1, and the discharge port 131 g connected to the inflow port141 a is formed in the fan case 131 along the first direction DR1.Therefore, it is possible to reduce the height H (specifically, to besmaller than the inner diameter D).

The drain generated in the internal space of the fan case 131 (wateraggregated in the internal space of the fan case 131) enters the insideof the chamber 14 via the discharge port 131 g and the inflow port 141a. In the combustion device 200, the seal member 144 is provided betweenthe inner periphery surface of the periphery wall 143 and the outerperiphery surface of the periphery wall 131 i. Therefore, the drain canbe suppressed from contacting the seal member 144.

In the combustion device 200, the fan case 131 is attached to thechamber 14 (top wall 141) by the fix member 145 from one side of thesecond direction DR2. In addition, in the housing 300, the opening part306 is provided on one side of the second direction DR2. Therefore,according to the water heating device 100, the fix member 145 is visiblefrom the opening part 306, and it is possible to easily remove the fixmember 145.

First Modified Example

The inflow port 141 a may also be formed at the center of the top wall141, when viewed in a plan view. In such case, in both of aconfiguration in which the fan case 131 is provided on one side of thechamber 14 in the third direction DR3 and a configuration in which thefan case 131 is provided on the other side of the chamber 14 in thethird direction DR3, the same chamber 14 can be shared.

Second Modified Example

While an example in which the groove 131 j is formed on the outerperiphery surface of the periphery wall 131 i is described above, it mayalso be that, in place of the groove 131 j, a ring-shaped groove isformed on the inner periphery surface of the periphery wall 143, and theseal member 144 is provided in the ring-shaped groove. In such case,like the case where the groove 131 j is formed, it is possible tosuppress the attachment of drain generated in the internal space of thefan case 131 to the seal member 144.

Third Modified Example

In the above, an example in which the fan case 131 and the chamber 14are respectively different members are described, the fan case 131 andthe chamber 14 may also be formed integrally (formed in one member). Insuch case, the seal member 144 is not required. Therefore, the number ofcomponents is reduced. Also, in such case, the design of the peripherystructure of the inflow port 141 a and the discharge port 131 g issimplified.

While the embodiments of the invention have been described above, it ispossible to make various modifications to the above embodiments. Inaddition, the scope of the invention is not limited to the aboveembodiments. The scope of the invention is indicated by the scope ofclaims and is intended to include all modifications within the meaningand scope equivalent to the scope of claims.

The embodiments are particularly suitable for a combustion device and awater heating device having the combustion device.

What is claimed is:
 1. A combustion device, comprising: a chamber; aburner; a fan case; and a fan, wherein the chamber has a top wall, onthe top wall, an inflow port penetrating through the top wall along afirst direction and in communication with an internal space of thechamber is formed, the burner is attached to the chamber, so as to bespaced apart from and face the top wall in the first direction, in thefan case, a discharge port penetrating through the fan case along thefirst direction and in communication with an internal space of the fancase is formed, the discharge port is connected with the inflow port,the fan is provided in the internal space of the fan case, and arotation axis of the fan is along the first direction.
 2. The combustiondevice as claimed in claim 1, wherein the fan case has a bottom wallpartially overlapped with the chamber when viewed in a plan view, andthe discharge port is formed in a portion of the bottom wall overlappedwith the chamber.
 3. The combustion device as claimed in claim 2,wherein in a portion of the bottom wall not overlapped with the chamber,a suction port penetrating through the bottom wall along the firstdirection and in communication with the internal space of the fan caseis formed.
 4. The combustion device as claimed in claim 1, wherein thechamber is further provided with a first periphery wall surrounding theinflow port and having a cylindrical shape protruding along the firstdirection, the fan case is further provided with a second periphery wallsurrounding the discharge port and having a cylindrical shape protrudingalong the first direction, the discharge port is connected to the inflowport by inserting the second periphery wall into inside of the firstperiphery wall, and a seal member is provided between an inner peripherysurface of the first periphery wall and an outer periphery surface ofthe second periphery wall.
 5. The combustion device as claimed in claim1, wherein the inflow port is located at a center of the chamber whenviewed in a plan view.
 6. The combustion device as claimed claim 1,wherein a height of the chamber in the first direction is smaller thanan inner diameter of the inflow port.
 7. The combustion device asclaimed in claim 1, wherein the chamber and the fan case are integrallyformed.
 8. A water heating device, comprising: a housing; a fix member;and the combustion device as claimed in claim 1, wherein the housing isopen on a side of a second direction orthogonal to the first direction,and the fan case is attached to the chamber by the fix member from aside of the chamber in the second direction.
 9. The combustion device asclaimed in claim 2, wherein the chamber is further provided with a firstperiphery wall surrounding the inflow port and having a cylindricalshape protruding along the first direction, the fan case is furtherprovided with a second periphery wall surrounding the discharge port andhaving a cylindrical shape protruding along the first direction, thedischarge port is connected to the inflow port by inserting the secondperiphery wall into inside of the first periphery wall, and a sealmember is provided between an inner periphery surface of the firstperiphery wall and an outer periphery surface of the second peripherywall.
 10. The combustion device as claimed in claim 2, wherein theinflow port is located at a center of the chamber when viewed in a planview.
 11. The combustion device as claimed in claim 3, wherein theinflow port is located at a center of the chamber when viewed in a planview.
 12. The combustion device as claimed in claim 4, wherein theinflow port is located at a center of the chamber when viewed in a planview.
 13. The combustion device as claimed claim 2, wherein a height ofthe chamber in the first direction is smaller than an inner diameter ofthe inflow port.
 14. The combustion device as claimed claim 3, wherein aheight of the chamber in the first direction is smaller than an innerdiameter of the inflow port.
 15. The combustion device as claimed claim4, wherein a height of the chamber in the first direction is smallerthan an inner diameter of the inflow port.
 16. The combustion device asclaimed claim 5, wherein a height of the chamber in the first directionis smaller than an inner diameter of the inflow port.
 17. A waterheating device, comprising: a housing; a fix member; and the combustiondevice as claimed in claim 2, wherein the housing is open on a side of asecond direction orthogonal to the first direction, and the fan case isattached to the chamber by the fix member from a side of the chamber inthe second direction.
 18. A water heating device, comprising: a housing;a fix member; and the combustion device as claimed in claim 3, whereinthe housing is open on a side of a second direction orthogonal to thefirst direction, and the fan case is attached to the chamber by the fixmember from a side of the chamber in the second direction.
 19. A waterheating device, comprising: a housing; a fix member; and the combustiondevice as claimed in claim 4, wherein the housing is open on a side of asecond direction orthogonal to the first direction, and the fan case isattached to the chamber by the fix member from a side of the chamber inthe second direction.
 20. A water heating device, comprising: a housing;a fix member; and the combustion device as claimed in claim 5, whereinthe housing is open on a side of a second direction orthogonal to thefirst direction, and the fan case is attached to the chamber by the fixmember from a side of the chamber in the second direction.